Lighting and ignition apparatus



J. H. HUNT ET AL Feb. 5, 1929.

LIGHTING AND IGNITION APPARATUS Original Filed Jan. 21, 1925 4 i 9 wrlblm .5. 83 0 '47 Patented Feb. 5, 1929.

lJNlTED STATES l dTENT OFFIQE.

JOHN H. HUNT, OF DETROIT. MICHIGAN. AND JOHN T. FITZSIMMONS, OF ANDERSON.

INDIANA, ASSIGNORS TO DELCO-REMY CORPORATION, OF DAYTON, OHIO, A CORPO- RATION OF DELAWARE.

LIGHTING AND IGNITION APPARATUS.

Original application filed January 21, 1925, Serial No. 3,732. Divided this application filed March 11, 1927. Serial No. 174,478.

This invention relates to electrical lighting and, ignition apparatus for automotive vehicles. such as light delivery trucks which do not carry a storage battery and motor for starting the engine.

This application is a division of Patent No. 'ljleleill issued Sept. 6, 1927, to J. H. Hunt and J. T. Fitzsimmons.

Pa ent No. 1,638,307, issued August 9, 1927, to John H. Hunt. disclrwcs an electrical light- 9- ionition system including a generator compi ng a lield magnet having pole face windings in which lighting current is "efieratoll. and a single rotor for generating an micrnat (r current for ignition purposes. It

; that this generator be driven by ie in fixed relation therewith. This no o apparatus requires a gear or chain l rocket drive between the engine and ral'or and cannot be belt driven.

()no of the objects of the present invention is to provide an electrical system of the type r erred to but including a generator having 0 face windings and a single rotor for gen erating lighting and ignition currents and which may be belt driven by the engine. Consequently this generator may be used intcrchangeably with a conventional type of belt driven direct current generator used on automobiles for charging the storage battery. This object is accomplished by providing a generator with a drum wound armature from which direct current is commutated for ignition purposes.

A further objrct is to minimize the fluctuations in the armature voltage and this is accomplished by a particular arrangement of the pole face teeth with respect to the armature core teeth.

A further object of the invention is to provide for the regulation of the ignition current in an ignition system including an induction coil and a generator of the type referred to.

A further object is to provide f or protection of the lighting circuit including the pole face win ing in case of accidental short circuiting of the generator armature.

Further objects of the present invention will be apparent from the following description, reference being had to the accompanying drawings, wherein a preferred form of embodiment of the present invention is clearly shown.

In the drawings:

Fig. 1 is a wiring diagram of the present invention.

Fig. 2 is an elevation of the brush structure of the machine.

Fig. is a fragn'icntary view looking in the direction of the arrow 3 in Fig.

The details of the frame of the dynamo 20, shown diagrammatically in Fig. 1, are completely disclosed in the riginal application referred to, but are omitted herein except for the fragmentary showing in Figs. 2 and 3. it will be understood that the frame of the dynamo supports an armature shaft 28 which carries an arn'iature and a commutator 31. The armature 30 is drum wound but differs from the ordinary direct current drum wound armature, in that the core teeth are relatively narrow and the ratio of copper and core iron is higher than shown in the conventional types. The dimensions of the armature which have been found satisfacmry are as follows: diameter 2.8 inches; length inches; 18 core slots; one coil per slot having 12 turns of #19 wire; each coil surrounds 8 teeth; and the armature core teeth are of an inch wide at the tip. In Fig. l, the armature core teeth are designated by numeral 32, and the windings each by numeral The pole pieces or stator poles 40 and 41 are laminated, the laminations being secured together by rivets 42. The laminations are attached to non-magnetizable rings one of which is indicated by numeral 43, by means of bolts 46 wh ch pass through the rings and laminations. The pole face teeth 50, 51, 52 and 53 of the pole piece 40 are located in a certain relation to the pole teeth 54, 55, 56 and 57 of the pole piece 41, and in a certain relation to the armature core teeth 32 as will be explained later. he polepieces to 57 inclusive are surroundeo, respectively, by pole face windings 60 to 67 inclusive. The windings Si, 62, 63, 65, 66 and 67 are connected so that their E. M. F.s will be cumulative and are connected with end terminals 68 and (39, and a center terminal T0. Each of the coils in this series has turns of #17 S. C. E. wire and the current generated therein is used to supply lighting current for the head lamps 72 and 73. The windings 60 and 64 are connected in series so that the E. M. F.s are cumulative. One end of this series of wind ings is connected with a terminal 7% and the other with a terminal 75. Each of these windings (50 and 61 has 140 turns of ;:29 C. E. wire and the cu 'rent generated therein is used for operating lamps of smaller candle power indicated at 76 and 77. These lamps be the cowl and tail lamps of the vehicle.

The field is excited by a pernnment magnet 80 ot' the horseshoe type. The poles oi the magnet are formed with accurate cylindrical faces 81 and 82 for fitting closely around the outer cylindrical surface ot the groups of laminations, comprising pole pieces it) and 41, A resistance element 88 is connected w ith an insulated or non-grounded connnutalor brush 90 and a grounded commutator brush 91.

The mounting of the brushes is shown in Figs. 2 and 3. A. box type bru:--:h holder 92 is attached to a non-conductor 9 3 which secured by rivets 94 to a wall ot' o l t dynamo end frames. The brush indicat z' 90 in Fig. 1 includes two brush elea nt :1 and 90' for a purpose to be tlC.'-Tt". Latex One of the brush elements. such as so" 1 a carbon brush relatively high in 1 l and the brush 90 is a metal relative y low resistance brush. The brushes 9G and W are connected by pigtails 97 with wrminal 98, and are engaged by brush springs 99" and 579*, respectively, having their ends lined to a portion 100 0% the brush holder 92. The brush holder 92 cooperates with a spacing element 101 tending to maintain the brushes 90 and 90 spaced from the non-conducting plate 93.

The pressure exerted by the brush spring 99 is sutlicient to maintain the carbon brush 90 in good electrical contact with t 1e courmutator throughout the speed in of dynamo operation, but the pressure exerted by the spring 99 is suflicient only to mi. in the heavier metal brush O0" in good contact with the comn'mtator a relatively low engine speeds. The other brush 91 indicated in F-l'. 1. includes elements 91 and 91 COII'CSPOntllIlQ.

respectively, to the brush elements 90 am 90 The brush holder 102 of the brush 91 is mounted directly upon a plate 103 wh attached to the end wall 95 by screws 103.

The commutator and brushes are enclosed by a cup sl aped frame (.Xl't .sien provided with OPQIIlIIfYS 111 to provide Zt'K'QSS to the brushes and coininutatm'. are covered by a cover band 112 social bolt 113 and nut 11.4.

Referring to Fig. 1 the dynamo l conncced by wi: ll with ignition 1' mz ry winding 12! v: ich is connec 122 with a switch flta t 123. 'l coil secondary 19% is connected wiil and with distributor 125 for d These o til op.

7 6i l sh o wn Ill l l, the timer 1 the QllQl'glZlllfj; and

ignition on which is l I 'n the armatu e 5 s i controls switch conixct 138 which 1S adapteo to l :hcr contact an or con ts i 2r A l l5 th out 1 to connect contacts l 'iil all 1 :1 will be connected p Y2, torn ii. wintteri'mnal T0, az'n'e 1:28, conthrough the fol.

' w llltllllgr; (3i

contacts 1:29 and to the lamp T l.

il be cong-- group o't pole face windings tl ro on a L l an :1 o ound rc .1

T2 lil icwi c 1 up T3 will he face windingzjs lamp T ter- 53. t Illlllilll T l wing; circuit lamp TY lamp I6. terminal pole face windings (B l; and (it), tern wire 132 and contacts 133 and ground return to the lamp head lamps T2 and (i-l. t l is moved to connect 1* The head lamp circuit only by introduc Lil :r-rl s with lamp." lamp: T6 and 77 will burn b circuit in the.- amps has lncn L y by the introduction o w head 5 135. c of o the 12: er lamp will coniniie each head lamp is counectrd v. 7.1 i 'l'ace windings.

In Case of short circuit of durin: the Operation of the 01 age or the po e lace wlndln matically regu ated so tl it tile volt.

turc ill). s pply the v mature reaction upon the dynamo field in such a manner as to crowd the flux toward the trailing pole teeth and awav from the leading pole teeth, therefore, the voltage generated by the windings (it) "nd 6i will be automatically limited to a state value tor the lamps in and 77. This armature reaction will tend to pull the field lluz: threading the armature from the pole tooth and toward the pole 53 and away from the pole 5.35 and toward the pole 57, but the total flux in the poles 5i, 5 525, 55, 5t; and 57 will be substantially the same so that the total E. M. F. generated in the group ot windings til, (32, (523 or the group of winding: (35, 66 and (37 will not be substantially higher than before the short circu t occurred. Hence voltage of the current delivered to the head lamps 72 and T3 will not become excessive due to the armature short circuit while the engine is running.

One of the important features of the present invention is that ot arranging the pole teeth with respect to the armature core teeth so that the fluctuation in arn'iature voltage will be minimized. its disclosed and claimed in the copcnding application oi John ll. llunt ret'erred to, it has been found a lvantageous in machines of this type to moire the spaciri of adjacent field pole teeth one and one-ha times the spacing the arniatn' 1 pole t el There is not a complete circle of pole teeth as it necessary to omit some of the teeth to provide a zone ol coinnniitation ol the armature. It a direct current armature is used and the teeth are arr-angel so that the windings of one pole are in phase with the wineings of the other, there will he s ca a fluctuation in voltage of the direct current windings as to cause the possibility of low speed ignition failure it the contacts open when the amnaturc current is too small. to produce a spark. It has been found, however, that by shitting the pole pieces the same amount toward the. symmetrical axes of the machine in order to brine: the windings of the poles out oi phase with each other, the fluctuation oi armature voltage will be sul'istantially re duced and a higher average attained. Satisfactory results have ben obtained when the indings of one pole are out of phase with the w ndings of a pole of opposite sign by from to 180 electrical degrees. For example, it the armature core has 13 teeth, the cycle of the alternating current occurs every 20 oi rotation of the core. The polar projection defined by the groups of teeth 50 to 53, and 54 to 5'? should be displaced from 5 to 10 from the conventional arrangement. In Fig. 1 l nes and y are used to designate the axes of the polar projections. and it will be noted that these axes are displaced about 10.

ll'hen a direct current machine of this type operating at va iable speed throughout the speed range there is a wide variation of armature voltage. The voltage must be high enough to provide ignition current when cranking the engine by hand. On the other hand it is necessary to limit the current ot the ignition coil to a safe value when the engine is operating at high speed. 'io arr-omplish this, the inductance of the ition c ii is relatively high. E coil tance of 11111. has been for The resistance of the coil should be as low possible consistent with good nianu uring products, since it is necessary that the rcsii tance of the ignition circuit be low in n ler to obtain sufiicient current for gnition at low engine speed. Thecoil ii .irtenceden ruines the resistance to some extent. For example. a primary coil resistance of .1 ohm has n cl] found siitis'lartory. 'ihe urinal ure resi tance should be as low as possible in order to obtain the maximum current; low engine speed. The resistance of the arniat urc circuit for an armature having dimensions given in the ex:- ample is about .65 ohm and this resistance includes the resistance of the brtshes "d the lead wires as well as the a mature co To obtain the required coil inductance t id low reistance the primary coil lZl may have ii i.

tr ns of #18 wire.

The re istance 88 across brush is for the purpose or absorbi 1 lance of the armature w ndin s when the breaker points of the timer i127 open. 'l'ui self-inductance may also be absorbed b condenser connected with the brushes 9t) and 91.

At low engine speeds the heavier metallic and low resistance brush elements lit!" and hi remain in good electrical contact with the commutator 31 so that the resistance of the armature circuit at low speeds will be relatively low. However, tor commuting during higher speeds of the engine the higher resistance carbon brushes have been found more satisfactory since they can be maintained in good electrical contact with the commutator without the excessive pressure required by the metal brush, and metal brushes would permit undesirably high short circuit current in the armature coils short circuited by the brushes at the higher engii 3. speeds. The springs 99" are adjusted so that the high resistance brush elements 90 and 91 will be maintained with good electrical contact with the commutator at all dynamo speeds. but the pressure exerted by brushes 99" will not be sutiicient to maintain the heavier metal brushes 90" and 91" in contact with the coin mutator at the higher engine speeds.

The generator constructed in accordance with the example given will produce satisfactory ignition at 100 R. P. M. and satisfactory operation at 400 R. P. M. or greater of two 6.3 volt, 21 c. p. lamps, and two 6.3 volts 2 c. p. lamps.

A dynamo constructed in accordance with ill? the present invention can be used interchangeably with the conventional types of D. C. generator used in two-unit automotive electric systems without requiring any change 'in the manner of mounting upon the chassis or en gine frame. This makes the system particularly adaptable to present methods of interchangeable manufacture. The greater demand at present is for the two-unit system. but the demand for an electrical lighting and ignition system without storage battery can be supplied immediately because the generator of the present invention can he installed in plilt't. of the usual battery charg ng generator, and the timer and distributor of the present systun can be the same a the apparatus used generally in battery ignition systems.

While the form of embodiment of the present invention. as herein ilisclc; d. rem-dilutes a preferred formJit is to be lliltlfll'r'iOOtl that other forms might be adopted. ail coming within the scope of the claims whir follow.

What is claimed is as iollows:

1. An electrical generator having Inutator and a pair of brushes for e p the commutator, one brush of pair being 0 lower electrical resistance than the other. and means for maintaining the l w resistance brush in good electrical engagement the generator commutator only at the lower speeds of the generator and for maintaining the high resistance brush in good electrical engagement with the commutator throughout the speed range of generator operation.

2. An electrical generator having a field and pole face windings for generating current, and a toothed rotor carrying other generating windings, the pole face windings beins so constructed and arranged that in case of accidental short circuit of the rotor wind ings, the current in the pole face windings will not be excessive.

3. An electrical generator having a plurality of toothed field pole pieces, pole face windings surrounding the leading pole teeth and connected cumulatively for supplying current to a work circuit, said. windings each being formed of a relatively large number of turns of relatively high resistance wire, other pole face windings surrounding the other pole teeth and connected cumulatively for supplying current to it second work circuit and each formed of turns of wire fewer in number than the turns of the first mentioned pole face windings and of lower resistance than the wire of the first mentioned pole face windings, and a toothed rotor carrying other generating windings.

4. An electrical generator having a plurality of field pole pieces,apluralityofsetsofgencrating coils carried by the pole pieces, one set having coils located only adjacent the leading portions of the pole pieces. and the other not having coils distributed over the remaining portions of the pole pieces, and a toothed rotor carrying other generating windings.

In testimony whereof we hereunto aiiix our signatures.

JOHN H. HUNT. JOHN T. FITZSIMMONS. 

